[PATCH] arm64: kvm: Avoid setting the upper 32 bits of VTCR_EL2 to 1
From: Will Deacon <hidden>
Date: 2018-12-13 16:05:52
Also in:
kvmarm, stable
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Although bit 31 of VTCR_EL2 is RES1, we inadvertently end up setting all of the upper 32 bits to 1 as well because we define VTCR_EL2_RES1 as signed, which is sign-extended when assigning to kvm->arch.vtcr. Lucky for us, the architecture currently treats these upper bits as RES0 so, whilst we've been naughty, we haven't set fire to anything yet. Cc: <redacted> Cc: Marc Zyngier <redacted> Cc: Christoffer Dall <redacted> Signed-off-by: Will Deacon <redacted> --- arch/arm64/include/asm/kvm_arm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 6f602af5263c..2dafd936d84d 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h@@ -104,7 +104,7 @@ TCR_EL2_ORGN0_MASK | TCR_EL2_IRGN0_MASK | TCR_EL2_T0SZ_MASK) /* VTCR_EL2 Registers bits */ -#define VTCR_EL2_RES1 (1 << 31) +#define VTCR_EL2_RES1 (1U << 31) #define VTCR_EL2_HD (1 << 22) #define VTCR_EL2_HA (1 << 21) #define VTCR_EL2_PS_SHIFT TCR_EL2_PS_SHIFT
--
2.1.4
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